1. Field of the Invention
The present invention relates, in general, to electrical watthour meters and, specifically, to watthour meter socket adapters and, more specifically, to jumper apparatus insertable into a meter socket for bypassing the watthour meter.
2. Description of the Art
In the electric utility industry, watthour meters are employed to measure electrical power consumption at a residential or commercial building site. A cabinet is physically mounted on the outside wall of the residence or building and contains a meter socket having pairs of lines and load terminals which are connected to electric power line conductors extending from the utility power network and electric load conductors connected to the residential or building power distribution network. The socket terminals are typically in the form of jaw contacts which receive the blade terminals extending outward from the base of a watthour meter in a snap-in connection to complete an electric circuit through the watthour meter between the line and load terminals mounted in the socket for the measurement of electrical power consumption.
Occasionally, one of the line terminals or jaw contacts in the meter socket burns out thereby disconnecting electric power to one side of the electrical power service. However, the other line terminal or jaw contact is usually still in operable condition and is capable of providing power to at least a portion of the load distribution network.
In order to enable electric power to be continued to be supplied to the residential or building site, even at a reduced level, and before the jaw contact or entire meter socket is repaired or replaced, electric utilities have frequently connected temporary jumpers between the still operable line jaw contact and one or both of the load contacts in the meter socket. Since the installation of separate jumper wires in a live meter socket poses a substantial safety risk, various devices have been devised which provide the desired jumper connection between one line contact and one or both of the load contacts in the meter socket in a simple, safe, plug-in manner.
For example, a meter socket jumper cover shown in FIG. 1 has been sold by Ekstrom Industries, Inc., the assignee of the subject invention. This meter socket jumper cover is in the form of an annular plastic disk having a handle mounted on an exterior side and at least one jumper mounted on the rear side. The jumper is in the form of an electrically conductive plate having at least one blade terminal formed thereon which is insertable into one of the line and load jaw contacts in the meter socket. One model of the jumper cover shown in FIG. 1 includes three blade terminals to provide a jumper between one line contact and two load contacts. This model provides power from one still operable line contact to both load contacts. A mirror image version is also available. Further, a third version includes two jumper strips, each extending from one line contact to one load contact.
Another previous attempt to provide a temporary bypass of a watthour meter to connect power to a load distribution network is shown in FIG. 2. A conventional watthour meter socket adapter includes a housing formed of an annular sidewall and a base and provided with a pair of load jaw contacts disposed within the housing and which extend to a blade terminal end, not shown, extending exteriorly of the housing and insertable into the load contacts in the meter socket. A jumper plate extends between and is connected to the two load jaw contacts as shown in the hidden lines in FIG. 2. A pair of apertures are formed in the socket adapter base at the standard low line contact positions and receive a blade terminal mounted at one end of a flexible conductor, the other end of which is connected to the jumper plate connected between the load jaw contacts in the socket adapter housing. The blade terminal may be inserted through either of the apertures in the base of the housing for connection to the still operable line jaw contact in the meter socket.
Another attempt to provide a watthour temporary watthour meter bypass is shown in FIG. 3. This device takes the form of a conventional watthour meter socket adapter base which has a handle, not shown, mounted on a cover attached to the base. Pairs of line and load blade terminals are mounted on and extend through the base and are insertable into respective line and load jaw contacts in the watthour meter socket. Pairs of fuse clips are mounted on the back surface of the cover and extend through an aperture formed in the base. Each fuse clip of each pair of fuse clips is connected to one of the blade terminals. Thus, a first pair of fuse clips are connected to one line and one load blade terminal, respectively. Another pair of fuse clips are connected to the opposite line and load blade terminals. A third pair of fuse clips are connected to each of the load terminals and to one of the fuse clips of the pair of fused clips connected to the line terminals. This arrangement provides three positions for the insertion of two standard 60 amp fuses which provide both overcurrent protection and a jumper connection between one of the line blade terminals and one or both of the load blade terminals.
However, while the above-described meter bypass jumper apparatus shown in FIGS. 1-3 provide a temporary bypass of a watthour meter in the event of a failure of one of the line contacts in a meter socket, such devices are not without their deficiencies. The prior art meter socket jumper cover shown in FIG. 1 requires separate versions to provide a connection between either of the still operable line contact and one or both of the load contacts. The meter socket jumper cover shown in FIG. 1 as well as the meter bypass apparatus shown in FIG. 2 lack fuses which would add a significant overcurrent safety feature to the use of such meter bypass jumper apparatus. While the meter bypass apparatus shown in FIG. 3 utilizes fuses for overcurrent safety, this apparatus is only capable of receiving low current fuses which thereby limits the amount of power which can be provided to the load distribution network on a temporary basis.
All of the above-described prior art watthour meter bypass jumper apparatus also lack any means for temporarily but securely storing a watthour meter on the apparatus when the jumper or bypass features are being utilized. According to electric utility standards, whenever a watthour meter is removed from a meter socket, it must be recalibrated for proper operation before it can be reinstalled into a watthour meter socket. Such recalibration of a removed watthour meter would not be necessary if the watthour meter could be mounted in an inoperable position on the meter socket while the meter bypass jumper features of the apparatus is being utilized.
While the socket adapter shown in FIG. 2 can receive a meter in the load jaws, such mounting is not secure unless a sealing ring is connected about the mounting flanges of the meter and the socket adapter. Prior to mounting the sealing ring, the meter can tip down.
Thus, it would be desirable to provide a watthour meter bypass adapter which temporarily bypasses a watthour meter to provide at least limited power to a load distribution network. It would also be desirable to provide a watthour meter bypass adapter which is usable regardless of which watthour meter socket line contact is inoperable. It would also be desirable to provide a watthour meter bypass adapter which has the capability of selectively connecting either line contact to either or both load contacts. It would also be desirable to provide a watthour meter bypass adapter which is capable of receiving high amperage fuses to provide a maximum amount of power to a load distribution network. Finally, it would be desirable to provide a watthour meter bypass adapter which has provisions for mounting a watthour meter in a storage position on the adapter during use of the watthour meter bypass features of the adapter.